It is the long range purpose of this project to study the chemistry and structure of collagen from the molecular to the fiber level. The topics of present interest are: 1. The chemistry and molecular form of Ascaris cuticle collagen. 2. The improvement of methods to isolate intact native collagen monomer. 3. The characterization of collagen fibril structure by the introduction and location of artificial crosslinks. 4. The relationship of the amino acid sequence of collagen to the fibril structure. 5. The mechanism of collagen fibril formation.